diff --git a/models/controller_dbo.cc b/models/controller_dbo.cc
index b4775e7..c96b9ee 100644
--- a/models/controller_dbo.cc
+++ b/models/controller_dbo.cc
@@ -43,6 +43,7 @@ static controller_dbo*
 controller_db_select_mapper(sqlite3_stmt *stmt)
 {
     auto *new_controller = new controller_dbo();
+    const char* new_tag;
     for(int i = 0; i < sqlite3_column_count(stmt); i++)
     {
         const char *name = sqlite3_column_name(stmt, i);
@@ -74,7 +75,12 @@ controller_db_select_mapper(sqlite3_stmt *stmt)
                 new_controller->relay_count = sqlite3_column_int(stmt, i);
                 break;
             case 't': // tag
-                strncpy(new_controller->tag, (const char*)sqlite3_column_text(stmt, i), 63);
+                new_tag = (const char*)sqlite3_column_text(stmt, i);
+                new_controller->tag[0] = '\0';
+                if(new_tag)
+                {
+                    strncpy(new_controller->tag, (const char*)sqlite3_column_text(stmt, i), 63);
+                }
                 break;
             default: // ignore columns not implemented
                 break;
diff --git a/models/relay_dbo.cc b/models/relay_dbo.cc
index 8847f43..f83ff93 100644
--- a/models/relay_dbo.cc
+++ b/models/relay_dbo.cc
@@ -34,6 +34,7 @@ static relay_dbo*
 relay_db_select_mapper(sqlite3_stmt *stmt)
 {
     auto *new_relay = new relay_dbo();
+    const char* new_tag;
     for(int i = 0; i < sqlite3_column_count(stmt); i++)
     {
         const char *name = sqlite3_column_name(stmt, i);
@@ -60,8 +61,14 @@ relay_db_select_mapper(sqlite3_stmt *stmt)
                     default:
                         break;
                 }
+                break;
             case 't': // tag
-                strncpy(new_relay->tag, (const char*)sqlite3_column_text(stmt, i), 63);
+                new_tag = (const char*)sqlite3_column_text(stmt, i);
+                new_relay->tag[0] = '\0';
+                if(new_tag)
+                {
+                    strncpy(new_relay->tag, (const char*)sqlite3_column_text(stmt, i), 63);
+                }
                 break;
             default: // ignore columns not implemented
                 break;
@@ -258,4 +265,4 @@ relay_dbo::free_list(relay_dbo **relays_list)
         delete relays_list[i];
     }
     free(relays_list);
-}
\ No newline at end of file
+}